Green’s Dictionary of Slang

1. (also gabby) a fool.

1792		G.S. Carey Dupes of Fancy 19: I’ll be hang’d if he be’ant as great a Gaby as myself.
1811		Lex. Balatronicum.
1818		W. Perry London Guide 226: He pulled it [i.e. a stolen watch] forth like a gaby .
1827		Egan Anecdotes of the Turf, the Chase etc. 201: Mr. Half-and-Half, (a precious gaby).
1834		Marryat Peter Simple (1911) 279: The marine officer is a bit of a gaby.
1838		‘Alfred Crowquill’ Seymour’s Humourous Sketches (1866) 3: I say — vot are you about ? Don’t put the shot in afore the powder, you gaby!
1840		Thackeray Shabby Genteel Story (1853) 32: That handsome gaby with the large beard.
1853		G.J. Whyte-Melville Digby Grand (1890) 48: He was nervous, absent, and dispirited, or, as Mrs Times remarked, ‘a greater gaby than ever.’.
1859		G.F. Atkinson Curry & Rice (3 edn) n.p.: [A]s for Chutney, his immediate superior, he considers him to he a downright gaby of the first water.
1867		R. Whiteing Mr Sprouts, His Opinions 7: The hair o’ most o’ the great gabies was parted down the middle.
1875		‘Ouida’ Signa I 47: ‘You have never dried your clothes, Bruno,’ said his sister-in-law. ‘What a gaby a man is without a wife!’.
1887		in G.D. Atkin House Scraps 29: And Villiam, like a reg’lar gaby, / Cloth’d the boy [...] In finery out of the ’Arrow Rode.
1893		R. Morton ‘O Lizer, Para-Lizer’ 🎵 Like a silly gaby, With a wife and half a baby, I’m on the job for better or wuss.
1900		Sun (NY) 14 Jan. 6/2: I set there starin’ arter thim, like a gaby at a fair.
1905		H.G. Wells Kipps (1952) 114: Well, you are a young Gaby [...] There jest been seein’ what a Gaby like you ’ud do.
1913		D.H. Lawrence Sons and Lovers (2003) 178: She is one of those who will want to suck a man’s soul out till he has none of his own left [...] and he is just such a gaby as to let himself be absorbed.
1926		Wood & Goddard Dict. Amer. Sl. 19: gabby. A simpleton.
1960		J.R. Ackerley We Think The World Of You (1971) 58: Should I disillusion the great gaby?

2. an effeminate man, a homosexual.

1922

‘J.H. Ross’ Mint (1955) 123: ‘And who let you into my flight, Gaby?’ The name stuck. [Ibid.] 128: Gaby thought she might assert the manhood our nickname denied her.